For example, as disclosed in JP 2004-201486 A, a method for detecting unsaturation of a semiconductor switching element has been heretofore known as a short-circuit protection function for a high-potential-side semiconductor switching element. When the semiconductor switching element is in a normally ON state, a voltage between terminals of the semiconductor switching element is a saturated voltage. However, when the semiconductor switching element is in a short-circuited state, the voltage between terminals of the semiconductor switching element rises from the saturated voltage due to an overcurrent and then becomes an unsaturated voltage. JP 2004-201486 A described above discloses a technique for performing short-circuit protection for the high-potential-side semiconductor switching element by detecting an unsaturated voltage to detect a short-circuited state of the high-potential-side semiconductor switching element. Note that “unsaturated” may be abbreviated as “DESAT”, and “unsaturated voltage” may be abbreviated as “DESAT voltage”.